Device for wet-processing leather and hides

ABSTRACT

A device for wet-processing leather and hides comprising a series of arcuately arranged rollers and a pressure roller whose surface bears upon all of the arcuately arranged rollers. The material to be treated is passed through the rollers which are disposed in a liquid bath with the length of treatment of the material being controlled by the amount of liquid in the bath and/or the speed of transferring the material through the rollers.

, 1 1 1111 States aten 1 1 H 11 3,902,338 Kessler Sept. 2, 1975 DEVICE FOR WET-PROCESSING LEATHER 1,809,909 6/1931 Pierini 69/28 RIDES 3,176,483 4/1965 Marse1lo.. 68 43 3,449,156 6/1969 Brown 653/22 R [75] Inventor: Hans Kessler, Aalen, Wurttemberg, 1

Germany FOREIGN PATENTS) OR APPLICATIONS [73] Assigneez Paul Faremzi, Germany, a part 998,843 9/1951 France 68/43 interest Primary Examiner-Alfred R. Guest [22] Flled 1973 Attorney, Agent, or Firm-Basile and Weintraub [2]] Appl. No.: 403,769

[57] ABSTRACT A D [30] Foreign pp [ca Mm Pnumy ata A device for wet-processing leather and hides com- Apl'. 26, Germany p g a series of arcuately arranged rollers and a pressure roller whose surface bears upon all of the ar- [52] US. Cl. 69/29; 68/43, 68/100 cuately arranged rouers The material to be treated is [5 Int. Clv passed h g h o s a i pos i a 58] Field 01 Search 69/29 30- 68/43 100 urd bath Wlth the length of treatment of the material 68/101 being controlled by the amount of liquid in the bath and/or the speed of transferring the material through [56] References Cited the renew UNITED STATES PATENTS 440,418 11/1890 Burnell 68/100 x 5 Clams 3 Drawmg F'gures DEVKTE lFOR WET-PROCESSING LEATHER ANI) HIDES BACKGROUND OF THE INVENTION I. Field of the Invention The present invention relates to a device for wetprocessing leather and hides and, in particular, to a device for wet-processing furs.

ll. Description of the Prior Art In order to convert furs and leather from the raw state to a usable condition, a plurality of process stages are required. For example, sheep skins have to be degreased, washed and tanned. Other process stages, depending upon the particular material being dealt with, include neutralizing, secondary tanning, greasing, dyeing, degreasing of tanned hides and other subsequent processes. The processes are much the same in leather production. A precondition in all cases is that the treatment liquids must penetrate into the skin.

The liquids or solutions used for these treatments have chemical compositions and concentrations which are in each case determined in accordance with the result to be obtained, and with the material being han dled.

In the treatment of leather and furs, it is well known to treat these materials with liquids having different chemical compositions. For degreasing, for example, solvents such as trichloroethylene or perchloroethylene and the like are used. It is well known in this context to carry out the treatment either by moving the product in a drum or in a boiler in which the hides are suspended without being imparted any movement. In both of these cases, the hides are dried after a corresponding processing time in the drum or boiler.

Also known is a method in which the leathers or hides to be treated, are passed through the treatment liquid contained in a bath, between spaced pinch rollers which are pressed into contact with one another. This method has the advantage compared with the methods hereinbefore described that with introduction of the leather or the hide into the bath, multiple soaking with the treatment liquid takes place. In passing through the first pair of pinch rollers, the liquid is pressed from the material again and after release by the pair of pinch rollers, the material expands and soaks up liquid again which, in the following pair of pinch rollers, arranged at a certain interval, is pressed again so that the sponge-like effect of expulsion and suction is repeated in accordance with the number of pairs of pinch rollers provided. This repeated sponge effect is advantageous in so far as the thoroughly satisfactory and at the same time gentle treatment is effected, whilst at the same time reducing the treatment time.

One device used to perform this known method, consists of an elongated bath which contains the treatment liquid, in which there are upper and lower screen conveyor belts, the top run of the lower conveyor belt and the bottom run of the upper conveyor belt passing between the pairs of pinch rollers which are arranged at intervals one after another. The device is also equipped with a drive system. The hide or leather for treatment is introduced at the entry end of the bath. between the two conveyor belts and drawn along by these through the liquid bath, each pair of pinch rollers located in the bath pressing out the liquid which the material has ab sorbed so that on its way to the particular next pair of pinch rollers, the material can soak up liquid again. At

the exit from the bath, there is a last pair of pinch rollers located above the bath, which squeezes out the sur plus liquid absorbed by the material. The treatment material is then directed into an ensuing conveyor belt for further processing. This known device, because of the fact that the pairs of pinch rollers are arranged one after the other in a horizontal plane, occupies a considerable amount of installed space. The length of the treatment line is fixed once and for all because of the conveyor belts passing through the bath so that the treatment time, when dealing, for example, with a sensitive material, can only be reduced by using higher transfer speeds, but this has a deleterious effect upon the treatment because on the one hand the sensitive material is more heavily loaded and on the other, because of the faster transit through the pairs of pinch rollers, the sponge effect is not so marked. The known device is thus not applicable with equal effect to any arbitrary material. Also, it is relatively elaborate in construction and operation because of the requisite driven conveyor belts which guide the materials.

SUMMARY OF THE INVENTION The object of the present invention is so to design this known device that it is universally suitable for all the materials which occur and all the requisite kinds of treatmeants, in an equal way, being distinguished by simplicity of construction, simplicity of assembly and reliable'operation whilst having a short installed length so that it occupies only a small amount of space, the novel design also making it possible to perform the treatment either in a liquid bath or between the rollers of the series by the dosed introduction of the treatment liquid to the material. In accordance with the invention, this object is achieved in that the pinch rollers consist of a series of rollers in a circular arcuate arrangement, and ofa pressure roller whose surface bears upon all the rollers of the series; and in that either the series of rollers, or the pressure rollers are provided with a drive. Because of the circular arcuate arrangement of the pinch rollers, the device has an optimally short length. The length of the treatment line in the device can, as will be explained later, be modified so that even sensitive material can still be processed at the same transfer speed. The provision of conveyor belts is no longer necessary because for one thing the rollers of the series are located closely adjacent to one another so that the material leaving one roller in the series is passed through the pressure drum of the next roller. The transfer speed can also be modified as a function of the particular material being processed.

Considering a device which serves to treat the mate rial in a liquid bath, the invention is characterized in that the circular arcuate series of rollers is arranged beneath the pressure roller in a bath containing the treatment liquid; in that the pressure roller is designated as a hollow body which can be wholly or partially filled with water, is cylindrical in form and rests freely on the bottom series of rollers; and in that between the individual rollers of the bottom series, smaller-diameter supporting rollers are provided. With this embodiment, the rollers of the bottom series are equipped with a drive system. Through the design of the pressure drum in accordance with the invention, as a hollow cylindrical body resting freely on the bottom series of rollers, it is possible to adjust the pinch pressure arbitrarily by varying the amount of water in the pressure drum so that in a simple fashion the pinch pressure can be adapted in each case to the desired, necessary conditions. The supporting rollers of small diameter arranged between the individual rollers of the bottom series and disposed at a short interval from the surface of the pressure drum, ensure reliable transfer of the material from one roller to the next of the series.

A further feature of the invention is characterized in that the bottom series of rollers encompass the upper pressure drum, at least around half its circumference.

If a long treatment path is required, then the bath is filled with the treatment liquid to such a level that all the rollers of the bottom series are in the liquid. If a shorter treatment path is required, then the level of the liquid bath is reduced correspondingly so that for the same transfer speed the treatment paths can be matched to the particular material being processed without any difficulty. If a longer treatment path should be needed, then more rollers can be provided, extending around virtually the whole circumference of the drum, the level in the bath having to be raised accordingly of course. Also, in order to lengthen or shorten the treatment time, the transfer speed can be modified.

The invention is also characterised by the fact that the rollers of the bottom series are individually springmounted in the radial sense vis-a-vis the pressure drum.

A further feature of the invention resides in the fact that in order to render the pressure exerted upon the rollers of the bottom series uniform, adjacent rollers of this series are linked with one another through lever systems.

Because the pressure exerted by the upper pressure drum on the bottom series of rollers is greatest in the neighborhood of the bottom crown portion of the drum, the pressure on the individual roller of the bot-' tom series can be rendered uniform by a lever system in accordance with the invention, so that all the rollers of the bottom series are loaded by the pressure drum with the same pressure. Thus each roller of the bottom series exerts the same pinch action. The lever system can fundamentally be of any desired design; for example, commencing from that roller of the bottom series which is located in the neighborhood of the bottom crown point of the pressure drum, the neighboring rollers of the bottom series can be linked with that roller through double-armed levers pivoted at their centers. The neighboring succeeding rollers, in turn,.are linked by double-armed levers so that the pressure exerted on the bottommost roller of the bottom series is transmitted to the rollers located adjacently at either side, and from these to the rollers which are next to them, and

so on.

A further feature of the invention is characterized in that all the rollers or individual ones in the bottom series are exchangeable and are equipped with a smooth surfce or with linings of differing hardness and absorptivities, for example linings of rubber, felt or the like.

A further feature resides in the fact that the circumferential surface of the upper pressure roller is provided with a smooth surface or with linings of differing hardness and absorptivities, for example of rubber, felt or the like.

Another essential feature is that the supporting rollers are exchangeable in design and are equipped with outward-extending spiral beads or grooves, spikes or brushes. The exchangeable supporting rollers, with their spiral beads or grooves extending outwards to either side from the center, are used to tauten the material on transition from one roller of the bottom series, to the next, and thus keep it smooth. It is convenient in this context to arrange for the transfer speed of the supporting rollers to be somewhat greater than that of the rollers in the series, the drive to the supporting rollers being, for example, effected through corresponding transmission elements from the drive system used to drive the series of rollers. If the hair side of a hide is to be intensively processed, for example, take the case of the degreasing of the wool in raw sheep skins, the supporting rollers are equipped with comb-like spikes or brushes which also extend spiral fashion from the center to either side.

A further feature of the invention resides in the fact that the bath containing the bottom series of rollers has a bottom wall of semi-circular shape parallel to the circular arcuate profile of the bottom series of rollers.

If, with the drum completely filled with water or where the level of the solution in the bath is too high, the pressure should be insufficient, then in accordance with the invention at the top crown point of the pressure drum an additional small-diameter pressure roller can be arranged.

Thanks to the facility for the adjustment of differing lengths of treatment path, i.e., by variation of the number of pinch operations, by variation of treatment time, i.e., by using different transfer speeds and differing pinch pressures with the upper pressure drum filled to different levels, the device in accordance with the invention can be adpated to correspond with any arbitrary material being processed and can be employed in an optimum way for each different kind of process. If, for example, a hide is to be washed, then it is introduced into the machine with the leather side towards the drum, and the projections, such as spikes, combs or brushes, arranged on the underlying supporting rollers, penetrate into the hair, reinforcing the cleaning of the hair side which is carried out by the successive pinch operations, so that proper cleaning is ensured. If, on the other hand, a tanned fur hide is to be degreased, then it is introduced into the machine with the hair side towards the drum so that it is eventually the leather side of the hide which comes into contact with the treatment liquid, thus ensuring proper degreasing.

In the same device, other processes can be carried out using other treatment liquids. Likewise, using the same device leather can be degreased, tanned, dyed etc. Impurities collecting during the treatment and, in particular, during washing, assemble at the bottom crown point of the circular arcuate base of the bath, and can be discharged in concentrated form without affecting the waste water.

A modified embodiment of the invention is characterized in that the rollers of the circular arcuate series are arranged above the pressure drum and, under the effect of a radial and preferably adjustable pressure exerted upon them, are held in contact with said drum, embracing it at least around half its circumference; and in that between all the rollers of the series and the pressure drum, nozzles which are directed into the exit nips of the rollers in the series and serving to apply the treatment liquid to the material, are provided.

In this embodiment, a liquid bath is dispensed with, this having an advantage in so far as the treatment liquid need not be used in surplus quantity. Instead, the treatment liquid is sprayed from the nozzles directly and in precisely metered quantities, onto the material and to the exit sides of the nips determined by the series of rollers on theone hand and the pressure drum on the other, so that the material compressed by the pinch rollers can soak up the sprayed-on treatment liquid the instant it starts to expand again on leaving the nip. By means of the ensuing roller, any fraction of the treatment liquid which has not penetrated, can be forced into the skin at the entry side of the-nip and immediately thereafter fresh treatment liquid can be sprayed into the exit side of the nip. A further advantage resides in the fact that in succession, different concentrations of one and the same treatment liquid can be applied to the materiaL Also, even during the transit of the material through the device, different chemicals can be successively applied to the material in the manner frequently necessitated in tanning, so that the modified embodiment of the device is particularly suitable for this application. The pressure drum arranged beneath the series of rollers is assembled in a fixed bearing and can be made-to rotate through the medium of a drive shaft. Here, of course, differing degrees of filling the pressure drum with water in order to achieve different pinch pressures are not possible. However, different pinch pressures can be produced by adjustment of the pressure elements acting upon the upperseries of rollers. In this embodiment again, it is possible to choose treatment paths of different lengths, by virtue of the fact that not all the nozzles are supplied with the treatment liquid. and instead only a number of nozzles corresponding with the particular desired treatment path length. This embodiment is advantageous vis-a-vis the embodiment dealt with earlier, in so far as whilst maintaining the facility for choice which the latter offers, it makes it possible, without the need to use a surplus amount of treatment liquid, to effect accurately dosed spraying, in accordance with the particular operations, with one treatment liquid or with different treatment liquids.

A further modified embodiment is characterised in that in order to treat the material at both sides, pressure drums equipped with an upper series of rollers and a lower series of rollers are arranged adjacent one another in such a fashion that the material leaving one pressure drum is picked up by the other pressure drum. This modified embodiment is advantageous in situations where both sides of the material are to be treated in direct succession to one another, without involving any additional transfer path. Here, in one pressure drum one side of the material is treated by spraying, whilst in the other drum the other side is treated. That pressure drum which has a bottom series of pinch rollers can be operated either with a liquid bath or with spray nozzles, in which latter case no liquid bath is needed,

BRIEF DESCRIPTION OF THE DRAWINGS Other objects, advantages and applications of the present invention will become apparent to those skilled in the art of wet processing devices when the following description of the present invention is read in conjunction with the accompanying drawings wherein like reference numerals refer to like parts throughout the several accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and in which:

As FIG. 1 shows, the device consists of a bath 2 with a circular arcuate base wall I. In the bath bottom rollers 3 are arranged in the form of a circular arc with each of the rollers 3 being supported by springs 4. On the circular arcuate series of rollers 3, there rests an I upper pressure drum 5 consisting of a hollowcylindrical body which, in order to achieve different pressures can be filled with water to any arbitrary level 6. The treatment liquid which is contained in the bath 1 can have its level 7 adjusted to different heights so that either all the rollers 3 or only some of them are located in the liquid. The aforementioned lever arrangements connecting the individual rollers 3 are not shown; however, the lever systems can be designed in any suitable manner. For example, the central roller 3 bearing against the bottom crown point of the top pressure drum 5, can be provided with respective double-armed levers leading to the neighboring rollers 3. These levers are arranged in the bath and pivoted at their centers. The two rollers adjacent the central roller 3 are, in turn, connected via a double-armed lever pivoted at its center with the two rollers adjacent to them,and so on.

In this fashion the highest pressure, i.e., that exerted by the pressure drum 5 on the bottom-most roller 3, is transmitted uniformally to the entire series of rollers 3. At the entry end of the bath 1, there is a guide plate 8 on which the hides or leathers to be treated, are intro duced between the first roller 3 and the pressure drum 5. The series of rollers 3 is driven by a suitable drive system (been shown) whilst the pressure drum 5 rests freely on the series of rollers 3 and rotates with them. After leaving the first roller 3, the material is able to relax and soaks up the treatment liquid fully until entering the next roller 3, after passing which it relaxes again. At the exit end of the bath 2, there is an upper roller 9 not located in the liquid 7 of the bath 2, which removes the surplus liquid from the material. Beneath the roller 9 there is a doctor plate over which the material is passed to a conveyor belt 11 which transports it onwards to a later processing station. As FIG. 1 shows, between each two rollers 3, there is a supporting roller 12 which ensures that the material adhering to the upper pressure roller is reliably supplied to the next roller. These supporting rollers 12 can be separately driven in order to give them a higher transfer speed than the rollers 3.

FIG. 2 illustrates a modified embodiment in which above the hollow cylindrical body 5 there is a circular arcuate series of pinch rollers .3. The individual rollers 3 are supported through adjustable springs 4, on a circular arcuate wall 14, said springs maintaining them in contact, with variable pressures, against the surface of the hollow body 5. Between the rollers 3 there are pipes with spray nozzles 13 arranged in such a fashion that the liquid which is to be applied to the material being treated is sprayed onto the point of exit of the material from the roller 3. At this point the material expands directly after exit from the roller 3 so that the liquid sprayed from the nozzles 13 can be soaked up by it. This spraying operation is repeated at the ensuing rollers 3. The introduction of the material for treatment takes place at a table 8 whilst after the last roller there is a doctor plate 10 over which the material is passed to a conveyor belt 11.

FIG. 3 illustrates an ancillary arrangement of two hollow cylindrical bodies 5, the first of which is provided on its surface with a circular arcuate series of rollers 3 whilst the other exhibits a circular arcuate series of rollers 3 arranged at its underside.

The material being treated is supplied on a conveyor belt 8 to the left hand drum and passes through the upper series of rollers 3, the top side of the material being sprayed by the nozzles 13. On leaving the left hand drum 5, the material is picked up directly by the right hand drum 5 and passes the bottom series of rollers 3 arranged in an arcuate form and assigned to this drum 5, where the opposite side of the material is likewise supplied with the treatment liquid through nozzles 13. Between the individual rollers 3, supporting rollers 12 are arranged in order to reliably transfer the material from one roller 3 to its neighbor. On leaving, the material passes an upper pinch roller 9 and is conveyed over a guide plate to a conveyor belt 11. Instead of the nozzles assigned to the bottom series of rollers 3, it is also possible to use a liquid bath of the kind shown in FIG. I.

I claim:

1. A device for wet-processing leather and hides in which the materials to be processed are soaked in a treatment liquid and passed through pinch rollers loaded into contact with one another and arranged at equal intervals from one another and characterized in that the pinch rollers comprise a series of rollers disposed in a circular, arcuate arrangement;

a bed roller whose surface bears against said pinch rollers and is supported soley by said pinch rollers;

said bed roller being a free floating, hollow cylindrical body having means for selectively filling said body with a fluid to vary the pressure of said bed roller against said series of bottom rollers;

a bath containing said treatment liquid, said circular, arcuate series of rollers beneath said bed roller being arranged in said bath; and

a means for moving said material by said series of rollers.

2. The device defined in claim 1 further comprising a pinch roller located at the exit end of said bath, said exit roller engaging said material against the preceding roller of said series of rollers to remove surplus treatment liquid from said material, said pinch roller exerting a pressure against said material at a point above the level of said treatment liquid.

3. The device defined in claim 1 further comprising individually spring mounted means for radially biasing said pinch rollers of said series into said bed roller.

4. The device defined in claim I wherein said bath, within which said series of rollers is disposed, has a semicircular base wall parallel to the circular, arcuate profile of said series of rollers.

5. The device defined in claim 1 further comprising supporting rollers disposed between the individual rollers of the bottom series of rollers, said supporting rollers being of a small diameter with respect to said series of rollers, said supporting rollers being adapted to readily transfer said material from roller to roller of said series of rollers.

UNITED STATES PATENT AND TRADEMARK OFFICE QERTEHCATE 0F QGRRECTION PATENT NO. 3,902,338 DATED September 2, 1975 INVENTOR(S) Hans Kessler It is certified that 8H0? appeais, aw 5m :lEDOVGwiE-Tfiifi'lbd pa em Fed that sair? Letter; Patent are hereby corrected as shown beow Page 1, line [73], after "Paul" delete "Farentzi" and insert -Fe1r:entzi-o Signed and fizaled this RUTH C. MASON Arresting Officer c. MARSHALL DANN Commissioner ufParenls and Trademarks 

1. A device for wet-processing leather and hides in which the materials to be processed are soaked in a treatment liquid and passed through pinch rollers loaded into contact with one another and arranged at equal intervals from one another and characterized in that the pinch rollers comprise a series of rollers disposed in a circular, arcuate arrangement; a bed roller whose surface bears against said pinch rollers and is supported soley by said pinch rollers; said bed roller being a free floating, hollow cylindrical body having means for selectively filling said body with a fluid to vary the pressure of said bed roller against said series of bottom rollers; a bath containing said treatment liquid, said circular, arcuate series of rollers beneath said bed roller being arranged in said bath; and a means for moving said material by said series of rollers.
 2. The device defined in claim 1 further comprising a pinch roller located at the exit end of said bath, said exit roller engaging said material against the preceding roller of said series of rollers to remove surplus treatment liquid from said material, said pinch roller exerting a pressure against said material at a point above the level of said treatment liquid.
 3. The device defined in claim 1 further comprising individually spring mounted means for radially biasing said pinch rollers of said series into said bed roller.
 4. The device defined in claim 1 wherein said bath, within which said series of rollers is disposed, has a semicircular base wall parallel to the circular, arcuate profile of said series of rollers.
 5. The device defined in claim 1 further comprising supporting rollers disposed between the individual rollers of the bottom series of rollers, said supporting rollers being of a small diameter with respect to said series of rollers, said supporting rollers being adapted to readily transfer said material from roller to roller of said series of rollers. 